Wednesday, January 30, 2008
Taking Notes
If six boys can fill up six notebooks in six weeks and four girls can fill up four notebooks in four weeks, how many notebooks can a class of twelve boys and twelve girls fill up in twelve weeks?
Subscribe to:
Post Comments (Atom)
5 comments:
60 b/c 12/6=2, 12*2=24
12/4=3, 12*3=36
36+24=60
60 notebooks in all
"six boys can fill up six notebooks in six weeks" => 12 boys can fill up 12 notebooks in 12 weeks
"four girls can fill up four notebooks in four weeks" => 12 girls can fill up 12 notebooks in 12 weeks
Totally, 12+12=24 (notebooks)
6 boys - 6 notebooks/6 weeks...which is another way of saying:
6 boys - 1 notebook/ 1 week
same for girls 4 girls 4 notebooks per 4 weeks is the same as 4 girls - 1 notebook per 1 week
so 12 boys can fill up twice as many as 6 boys which is: 12 boys 2 notebooks/week
and 12 girls can fill up three times as much as 4 girls which is: 12 girls 3 notebooks/ week.
How many note books filled in 12 weeks?
12*3+12*4= 60 notebooks
The correct answer is 60
6b=(6n)/(6w)
6b=n/w
b=n/(6w) <---1 boy can fill 1 notebook in 6 weeks
4g=(4n)/(4w)
4g=n/w
g=n/(4w) <---1 girl cn fill 1 notebook in 4 weeks
So, 12 boys in 12 weeks + 12 girls in 12 weeks can be written as
(12b)(12w) + (12g)(12w)
(144n/(6)) + (144n/(4))
24n + 36n
60n <--- 60 notebooks can be made total
ct said wrong
Post a Comment